1. Field of the Invention
The present invention concerns a method and a system permitting a user to mix synthetic images and video images in real time.
More precisely, the subject matter of the invention is a method and a system enabling a user:
(i) to produce in a data processing unit, composed of standard electronic circuits, a flow of synthetic images, and
(ii) to trace a scene by creating visual interactions between the flow of synthetic images and at least one flow of video images.
The solution of this problem presented by the invention permits improving the quality of the scene and to shorten the processing time without employing proprietary and expensive data processing units.
2. Background
An equipment according to the prior art is represented in FIG. 1 which permits the achievement of the improved reality. This equipment includes;                a graphic work station STG,        a rack of the “chroma keyer” type RCK,        a rack of the “image delay” type RRI.        
The legends C and SV indicate respectively a camera and a video output.
The graphic work station STG is used for the generation only of synthetic images. The graphic work statio STG is developed specifically or is a Silicon Graphics™ station. The synthetic images are generated on a uniform color background (key color).
The “chroma keyer” type rack RCK is used for mixing the video image from the camera (C) with the synthetic image generated by the graphic station STG. The key color is replaced by the video image.
The “image delay” type rack RRI is used to compensate for the processing time of the image generator.
Drawbacks of the prior technology:
Equipment of the prior art present problems in regard to price and image qualities and functionality.
Problems in regard to price:
The cost price of the equipment of the prior art is very high. In fact, the “image delay” rack RRI is a professional rack, the graphic station STG is a professional station. The previous solution according to the prior art is not carriable(it is made up of three separate modules: image generator/image delay/ chroma key).
Problems in regard to image quality and functionality:
Visual interactivity between the video and the synthetic images is limited. In fact, at the output from the “chroma keyer” RCK the video is inserted in place of the key color. It is not possible to have reflections of the video on the synthetic images or vice versa. The video cannot be treated as a texture. For example, it cannot have reflection effects between the real images (video images) and the synthetic objects. The very principle of the “chroma key” can produce artefacts; it limits selection in the color palette of synthetic images, and makes the rendition of synthetic objects that have transparencies problematical.
The performance of specific graphic stations is quickly exceeded by the performance of consumer graphic boards which are ever more powerful (graphic power of consumer equipment is doubled about every six months).
The previous solution is expensive in terms of maintenance (the three units composing it involve a specific maintenance contract).
The previous solution cannot operate in a portable computer; it is not mobile.
The previous solution is constraining as regards time involved in adjusting all its parts.
On processing of the video image is possible:                the video cannot be used to texturize locally any element of the virtual scene,        the video cannot be shaped (for example the correction of optical distortions is impossible),        no processing can be performed on the video (for example, processing of the chroma key type).        